Abstract: The extrusion and accumulation of the slurry under different layer height were analyzed aiming at extrusion ceramic 3D printing for the preparing of casting shell. After 3D printing test, appropriate process parameter values were obtained by comparative studying the effect of extrusion head inner diameter, layer height and printing speed on printing process and printing quality, and the maximum space tilt angle and minimum angle in the printing plane of the printed part were obtained by comparative studying the quality of the printed part under different space tilt angle and the angle in the printing plane. The results show that appropriate process parameters are extrusion head inner diameter of 0.6 mm~0.8 mm, layer height of about 0.6 mm, printing speed of 20 mm/s. The maximum exterior and interior tilt angle of the printed part are 40°. The minimum angle in the printing plane of the printed part is 30°.